The Raw Materials of BiotechnologyChapter 2

Learning Outcomes

Identify the levels of biological organization and explain their relationships

Describe cell structure and its significance in biotechnology research and product development

Discuss the types of organisms researched and the types of cells grown and studied in biotechnology facilities plus the products with which they are associated

Distinguish between the cellular organization of prokaryotic and eukaryotic cells

List the four main classes of macromolecules and describe their structure and function

Define genetic engineering and identify products created with this technology

Explain the Central Dogma of Biology and its importance in genetic engineering

2.1 Organisms and Their Components

• To manufacture biotechnology products, biotechnicians must work with organisms and their components.

• These are the “raw materials” of biotechnology.

The Living Condition• Living things include:

• Plants• Animals• Bacteria• Fungi• Protozoans

• Characteristics of life:• Growth• Reproduction• Response to stimuli• Breakdown of food

molecules• Production of waste

products

Levels of Biological Organization

• Cells of multicellular organisms are usually grouped into functional units:• Tissues• Organs

• Cells are the smallest units of life. Some cells contain even smaller, nonliving units.

Vocabulary

• Fluorometer – an instrument that measures the amount or type of light emitted

• Organism – a living thing• Cell – the smallest unit of life that makes up all living organisms• Escerichia coli - a bacterium that is commonly used by biotechnology

companies for the development of products• Multicellular – composed of more than one cell• Cytology – cell biology• Anatomy – the structure and organization of living things• Physiology – the processes and functions of living things• Respiration – the breaking down of food molecules with the result of

generating energy for the cell• Unicellular – composed of one cell• Tissue – a group of cells that function together (eg, muscle tissue or nervous

tissue)• Organ – tissues that act together to form a specific function in an organism

(eg, stomach that breaks down food)

Vocabulary

• Proteins – one of the four classes of macromolecules; folded, functional polypeptides that conduct various functions within and around a cell (eg, adding structural support, catalyzing reactions, transporting molecules)

• Eukaryotic/eukaryote – a cell that contains membrane-bound organelles• Protist – an organism belonging to the Kingdom Protista, which includes protozoans,

slime molds, and certain algae• Organelles – specialized microscopic factories, each with specific jobs in a cell• Mitochondria – membrane-bound organelles that are responsible for generating

cellular energy• Sugar – a simple carbohydrate molecule composed of hydrogen, carbon, and oxygen• Starch – a polysaccharide that is composed of many glucose molecules• Nucleic acid – a class of macromolecules that directs the synthesis of all other

cellular molecules; often referred to as “information-carrying molecules”• Lipids – one of the four classes of macromolecules; includes fats, waxes, steroids,

and oils• Pancreas – an organ that secretes digestive fluids as well as insulin• Hormone – a molecule that acts to regulate cellular functions

2.1 Review Questions

1. Give an example of a plant that has been produced by biotechnology.

2. Knowledge of what other disciplines of science will improve the understanding of biotechnology?

3. Describe two characteristics of living things.

4. Which of the following is considered to be “alive”: organs, molecules, atoms, cells, or organisms?

2.2 Cellular Organization and Process

• Cells produce different molecules.• Hundreds of different molecules can be produced.

The Structure of Cells

• Cell walls• Cellulose fibers• Plasma membrane• Nucleus

Plant cell. Most plant cells contain chloroplasts and a rigid cell wall. Animal cells do not possess cell walls.

Animal cell. Animal cells do not have a cell wall and, thus, do not have a rigid cell boundary. The shapes of animal cells are quite diverse due to the flexibility of the outer membrane and the response when cells touch each other.

The Central Dogma of Biology. The Central Dogma of Biology states that DNA codes for RNA and that RNA codes for proteins (DNA -> mRNA -> proteins). Once scientists had described the Central Dogma, they could propose and test strategies for manipulating protein production by manipulating DNA and RNA codes. Moving genes into cells to produce new proteins is the basic principle in genetic engineering.

Shown in cell culture, these CHO cells are a common mammalian cell line used to manufacture recombinant protein.

Each rod-shaped structure in this electron micrograph is an E. coli cell. E. coli cells are simple prokaryotes with no membrane-bound organelles, such as mitochondria or chloroplasts.

Types of Cells Used in Biotechnology

• Plant cells• Animal cells• Bacteria cells• Fungal cells

Vocabulary

• Chlorophyll – the green-pigmented molecules found in plants; used for photosynthesis (production of chemical energy from light energy)

• Photosynthesis – a process by which plants or algae use light energy to make chemical energy

• Chloroplast – the specialized organelle in plants responsible for photosynthesis (production of chemical energy from light energy)

• Cytoplasm – a gel-like liquid of thousands of molecules suspended in water, outside the nucleus

• Lysosome – a membrane-bound organelle that is responsible for the breakdown of cellular waste

• Ribosome – the organelle in a cell where proteins are made• Cell wall – a specialized organelle surrounding the cells of plants, bacteria, and

some fungi; gives support around the outer boundary of the cell• Cellulose – a structural polysaccharide that is found in plant cell walls• Plasma membrane – a specialized organelle of the cell that regulates the

movement of materials into and out of the cell• Glucose – a 6-carbon sugar that is produced during photosynthesis reactions;

usual form of carbohydrate used by animals, including humans

Vocabulary

• Adenosine triphosphate – a nucleotide that serves as an energy storage molecule

• Nucleus – a membrane-bound organelle that encloses the cell’s DNA• Chromosomes – the long strands of DNA intertwined with protein

molecules• Enzyme – a protein that functions to speed up chemical reactions• Pigments – the molecules that are colored due to the reflection of

specific wavelengths• Messenger RNA (mRNA) – a class of RNA molecules responsible for

transferring genetic information from the chromosomes to ribosomes where proteins are made; often abbreviated mRNA

• Amino acids – the subunits of proteins; each contains a central carbon atom attached to an amino group (-NH2), a carboxyl group (-COOH), and a distinctive “R” group

• Polypeptides – a strand of amino acids connected to each other through peptide bonds

• Chinese hamster ovary (CHO) – an animal cell line commonly used in biotechnology studies

• Vero cells – African green monkey kidney epithelial cells• HeLa cells – human epithelial cells• Prokaryotic/prokaryote – a cell that lacks membrane-bound organelles

2.2 Review Questions

1. Which of the follow structures are found in prokaryotic cells: a nucleus, ribosomes, mitochondria, a plasma membrane, or one or more chromosomes?

2. Which of the following structures are found in eukaryotic cells: a nucleus, ribosomes, mitochondria, a plasma membrane, or one or more chromosomes?

3. Describe the relationship between chromosomes, mRNA, and proteins.

4. Explain how so many cells from the same organism can look so different from each other.

2.3 The Molecules of Cells

• Engineered molecules are the basis of many biotechnology products.

• Cells are composed of a variety of molecules.• Many molecules found in cells are much larger than atoms.• Very large molecules are found in structural components.

Carbohydrates• Carbon, hydrogen, and oxygen• Ratio 1:2:1

Polysaccharides• Excellent structural and energy-storing

molecules• Plants store glucose in starch molecules

Monosaccharides• Monomer units that cells use to build

polysaccharides• Most well known is glucose; an energy molecule

Structural Formula of Amylopectin. Amylopectin is one form of plant starch, and amylose is another. Plant starch, such as corn starch, is a key ingredient in many foods.

Structural Formula Glucose. Glucose is a 6-carbon sugar (C6H12O5) produced by plants during photosynthesis. Most plants use glucose as an energy source.

Structural Formula of 5-carbon Sugars. Deoxyribose (left) and ribose (right) are structural 5-carbon sugars found in the nucleic acids, DNA and RNA, respectively. Do you see the difference in their structure?

Disaccharides• Produced when enzymes form a bond between two

monosacchrides• Sucrose is made when fructose and glucose are chemically

combinedLipids• Often referred to as hydrocarbons• Three groups of lipids

• Triglycerides• Phospholipids• Steroids

Structural Formula of Maltose. Maltose is a disaccharide composed of two glucose molecules bound at carbon No.1 and carbon No.4. When organisms digest maltose, the bond holding the glucose monomers together is broken and energy is released.

Proteins• The most important of the cellular

molecules• Nine different categories of proteins

• Structural• Enzyme• Transport• Contractile• Hormone• Antibody• Pigment• Recognition• Toxins

• A typical cell produces more than 2000 proteins

• Amino acids are the monomers of proteins• There are 20 different amino acids found in

proteins

Nucleic Acids

• The fourth major group of macromolecules

• Two types of nucleic acids

• DNA• RNA

Polypeptide Strand. A polypeptide strand is made of amino acids connected to each other through peptide bonds. A folded, functional polypeptide chain is called a protein. Each protein has a specific amino acid sequence and folding pattern.

Two Nucleotides. A nucleotide is a molecule composed of a nitrogenous base (in pink), a 5-carbon sugar (in yellow), and a phosphate group (in blue).

Vocabulary

• Macromolecule – a large molecule usually composed of smaller repeating units chained together

• Organic – molecules that contain carbon and are only produced in living things• Carbohydrates – one of the four classes of macromolecules; organic compounds

consisting of carbon, hydrogen, and oxygen, generally in a 1:2:1 ratio• Cytoskeleton – a protein network in the cytoplasm that gives the cell structural

support• Monomers – the repeating units that make up polymers• Polymer – a large molecule made of many repeating subunits• Monosaccharide – the monomer unit that cells use to build polysaccharides; also

known as a “single sugar” or “simple sugar”• Disaccharide – a polymer that consists of two sugar molecules• Polysaccharide – a long polymer composed of many simple sugar molecules

(usually glucose or a variation of glucose)• Fructose – a 6-carbon sugar found in high concentration in fruits; also called fruit

sugar• Sucrose – a disaccharide composed of glucose and fructose; also called table sugar• Lactose – a disaccharide composed of glucose and galactose; also called milk sugar• Amylose – a plant starch with unbranched glucose chains

Vocabulary

• Amylopectin – a plant starch with branched glucose chains• Glycogen – an animal starch with branched glucose chains• Cellular respiration – the process by which cells break down glucose to create

other energy molecules• Deoxyribose – the 5-carbon sugar found in DNA molecules• Hydrophobic – repelled by water• Triglycerides – a group of lipids that includes animal fats and plant oils• Ribose – the 5-carbon sugar found in RNA molecules• Phospholipids – a class of lipids that are primarily found in membranes of the cell• Hydrophilic – having an attraction for water• Steroids – a group of lipids whose functions include acting as hormones

(testosterone and estrogen), venoms, and pigments• R group – the chemical side-group on an amino acid; in nature, there are 20

different R groups that are found on amino acids• Ribonucleic acid – the macromolecule that functions in the conversion of genetic

instructions (DNA) into proteins• Nucleotides – the monomer units of nucleic acids

2.3 Review Questions

1. Which of the following are monosaccharides: cellulose, sucrose, glucose, lactose, fructose, or amyolpectin?

2. Which of the following molecules are proteins that function as hormones: estrogen, insulin, human growth hormone, testosterone, or cholesterol?

3. What distinguishes one amino acid from another?

4. How are the terms nucleotide, nitrogenous base, and nucleic acid related to each other?

2.4 The “New” Biotechnology

• The most significant breakthrough came when scientists learned how to move pieces of DNA within and between organisms.

• The first genetic engineering occurred in 1973.• The first genetically engineered product to reach the

marketplace was human insulin.

2.4 Review Questions

1. What term is used to describe DNA that has been produced by cutting and pasting together pieces of DNA from two different organisms?

2. What organism was the first to be genetically engineered?

3. What was the first commercial genetically engineered product?

Questions and Comments?